AD/Convair/12 Main Landing Gear Piston/Axle Assemblies (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Kelowna Flightcraft (General Dynamics/Convair) Series Aeroplanes

AD/CONVAIR/12 Main Landing Gear Piston/Axle Assemblies 5/2006

Applicability:

Model 340 and 440 aircraft, and all such model aircraft converted to turbopropeller power.

Requirement:

1.    Inspect main landing gear Piston/Axle Assemblies part number 528039 with 10,000 or more hours time in service for crack indications in the fillet radius area between the axle and the outboard face of both brake attachment flanges, by dye penetrant inspection procedures; in accordance with Part I of General Dynamics 640 (340D) Service Bulletin (SB) No.32-3, dated 31 October 1969, or by magnetic particle inspection procedure.

2.    If no cracks are detected, repeat the Requirement 1 inspection.

The Requirement 2. 1,000 hour inspection interval may be terminated when the inspection area identified above has been reworked in accordance with paragraphs C, D, and E of Part II of SB 32-3.

Subsequent to the accumulation of 2,000 hours time in service after the rework, and before 2,500 hours time in service after rework, perform a Requirement 1 inspection for cracks.  If no cracks are detected during this inspection, further inspections are not required by this Directive.

3.    If cracks are detected during any inspection, accomplish the following:

a.     Rework the cracked area in accordance with all the provisions of Part II of SB 32-3, provided the axle wall thickness remaining after rework is a minimum of 0.30-inches. After rework, repeat the Requirement 1 inspection.

b.    If cracks are detected which require removal of material that would leave a minimum axle wall thickness of less than 0.30-inches, replace the axle.

Note:  FAA AD 70-12-07 Amdt 39-1004 refers.

Compliance:

1.    Unless the initial inspection is already accomplished, within 150 hours time in service after 11 May 2006, unless already accomplished within the last 850 hours time in service.

2.    At intervals not to exceed 1,000 hours time in service.

3.    Before further flight.

3.a. At intervals not to exceed 2,500 hours time in service.

This Airworthiness Directive becomes effective on 11 May 2006.

Background:

The FAA requires inspection of the main landing gear axles to detect cracks.  Undetected cracking could result in failure of the axle.

David Villiers
Delegate of the Civil Aviation Safety Authority

29 March 2006